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Background: The contributions of the gut microbiota to obesity and metabolic disease represent a potentially modifiable factor that may explain variation in risk between individuals. This study aimed to explore relationships among microbial composition and imputed functional attributes, a range of soluble metabolic and immune indices, and gene expression markers in males with or without evidence of metabolic dysregulation (MetDys)., Methods: This case-control study included healthy males (n=15; 41.9±11.7 years; body mass index [BMI], 22.9±1.2 kg/m 2 ) and males with evidence of MetDys (n=14; 46.6±10.0 years; BMI, 35.1±3.3 kg/m 2 ) who provided blood and faecal samples for assessment of a range of metabolic and immune markers and microbial composition using 16S rRNA gene sequencing. Metagenomic functions were imputed from microbial sequence data for analysis., Results: In addition to elevated values in a range of traditional metabolic, adipokine and inflammatory indices in the MetDys group, 23 immunomodulatory genes were significantly altered in the MetDys group. Overall microbial diversity did not differ between groups; however, a trend for a higher relative abundance of the Bacteroidetes ( P =0.06) and a lower relative abundance of the Verrucomicrobia ( P =0.09) phyla was noted in the MetDys group. Using both family- and genera-level classifications, a partial least square discriminant analysis revealed unique microbial signatures between the groups., Conclusion: These findings confirm the need for ongoing investigations in human clinical cohorts to further resolve the relationships between the gut microbiota and metabolic and immune markers and risk for metabolic disease.

Background: Early phase clinical research provided initial support for the use of a multispecies probiotic supplement to improve quality of life (QoL) in adults with seasonal allergic rhinitis (AR) and reduce the use of AR symptom relieving medication. This study aimed to confirm these early phase findings in a double-blind randomized placebo-controlled trial. Methods: Individuals, aged 18-65 years, with a minimum 2-year history of AR, moderate-to-severe AR symptoms, and a positive radio-allergosorbent test to Bermuda (Couch) Grass were randomized to receive either a multispecies probiotic supplement (total colony-forming units 4 × 10 9 /day) or placebo twice daily for 8 weeks. A mini-rhinoconjunctivitis quality of life questionnaire (mRQLQ) scale was administered at screening, days 0, 28, and 56. The proportion of participants with a >0.7 improvement in mRQLQ was the primary outcome. Participants also completed a daily symptom and medication diary during the supplementation period. Results: There were 165 participants randomized, with 142 included in the primary outcome analysis. The percentage of participants meeting the threshold for a clinically meaningful reduction in the mRQLQ from days 0 to 56 was not significantly different between groups (61% vs. 62%, p  = 0.90). However, 76 participants had a clinically meaningful improvement in QoL (decrease in mRQLQ >0.7) prior to the start of supplementation (screening to day 0). Conclusion: Changes in self-reported QoL and other disease severity metrics between screening and the start of supplementation limited the ability to discern an effect of supplementation and highlight the need for adaptive clinical trial designs in allergy research. Clinical Trial Registration: The trial was registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12619001319167).

Background: Nontypeable Haemophilus influenzae (NTHi) is the most common bacterial otopathogen associated with otitis media (OM). NTHi persists in biofilms within the middle ears of children with chronic and recurrent OM. Australian Aboriginal children suffer exceptionally high rates of chronic and recurrent OM compared to non-Aboriginal children. NTHi protein vaccines comprised of antigens associated with both adhesion and persistence in a biofilm are under development and could be beneficial for children with chronic and recurrent OM. Understanding the ontogeny of natural antibody development to these antigens provides insight into the value of vaccinating with particular antigens., Methods: An in-house multiplex fluorescent bead immunoassay was used to measure serum IgG titres and avidity for three putative vaccine antigens: recombinant soluble PilA (rsPilA), ChimV4, and outer membrane protein 26 (OMP26) in sera from Australian Aboriginal otitis-prone children (n=77), non-Aboriginal otitis-prone children (n=70) and non-otitis-prone children (n=36). Serum IgG titres were adjusted for age, and geometric mean concentrations (GMCs) were compared between groups using a univariate analysis model. Antibody avidity was calculated as a relative avidity index and compared between groups using ANOVA., Results: Australian Aboriginal otitis-prone children had lower serum IgG titres to rsPilA and ChimV4 than non-Aboriginal otitis-prone children (p<0.001), and non-otitis-prone children (p<0.020). No differences were observed between serum IgG titres from non-Aboriginal otitis-prone children and non-otitis-prone children. There were also no differences in the proportion of high avidity IgG specific for these antigens between these groups. Serum IgG titres to OMP26 were similar between all groups (p>0.670) although otitis-prone children had a higher proportion of high avidity antibodies to this antigen., Conclusions: Australian Aboriginal otitis-prone children had lower serum IgG titres to 2/3 major NTHi vaccine candidate antigens, suggesting these children are unable to develop persistent IgG responses due to repeated NTHi exposure. These reduced IgG titres may relate to earlier and more frequent exposure to diverse NTHi strains in Aboriginal children through carriage or infection. These data suggest that Aboriginal children may benefit from immunisation with vaccines containing these antigens to increase titres of protective antibodies., Competing Interests: LB is an inventor of technology related to PilA-derived immunogens that is licensed to GlaxoSmithKline Biologicals. PR reports receiving funds to his institution from GlaxoSmithKline for investigator led research and participation in vaccine scientific advisory boards outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Clark, Seppanen, Kirkham, Novotny, Bakaletz, Cripps, Corscadden, Coates, Vijayasekaran, Richmond and Thornton.)

Background: Otitis media (OM) is one of the most common infections in young children, arising from bacterial and/or viral infection of the middle ear. Globally, Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are the predominant bacterial otopathogens. Importantly, common upper respiratory viruses are increasingly recognized contributors to the polymicrobial pathogenesis of OM. This study aimed to identify predominant bacteria and viruses in the nasopharynx, adenoids and middle ears of peri-urban/urban South-East Queensland Australian children, with and without clinical history of chronic otitis media with effusion (COME) and/or recurrent acute otitis media (RAOM)., Methods: Sixty children, 43 diagnosed with OM and 17 controls with no clinical history of OM from peri-urban/urban South-East Queensland community were recruited to the study. Respiratory tract bacterial and viral presence were examined within nasopharyngeal swabs (NPS), middle ear effusions (MEE) and adenoids, using real-time polymerase chain reaction (RT-PCR) and bacterial culture., Results: At least one otopathogen present was observed in all adenoid samples, 86.1% and 82.4% of NPS for children with and without OM, respectively, and 47.1% of the MEE from the children with OM. NTHi was the most commonly detected bacteria in both the OM and control cohorts within the adenoids (90.0% vs 93.8%), nasopharynx (67.4% vs 58.8%) respectively, and in the MEE (OM cohort 25.9%). Viruses were detected in all adenoid samples, 67.4% vs 47.1% of the NPS from the OM and control cohorts, respectively, and 37% of the MEE. Rhinovirus was the predominant virus identified in the adenoids (85.0% vs 68.8%) and nasopharynx (37.2% vs 41.2%) from the OM and control cohorts, respectively, and the MEE (19.8%)., Conclusions: NTHi and rhinovirus are predominant otopathogens within the upper respiratory tract of children with and without OM from peri-urban and urban South-East Queensland, Australia. The presence of bacterial otopathogens within the middle ear is more predictive of concurrent URT infection than was observed for viruses, and the high otopathogen carriage within adenoid tissues confirms the complex polymicrobial environment in children, regardless of OM history., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ngo, Massa, McMonagle, Perry, Nissen, Sloots, Thornton and Cripps.)

Background: The combination of the antihistamine azelastine (AZE) with the corticosteroid fluticasone propionate (FP) in a single spray, has been reported to be significantly more effective at reducing allergic rhinitis (AR) symptoms than treatment with either corticosteroid or antihistamine monotherapy. However, the biological basis for enhanced symptom relief is not known. This study aimed to compare gene expression profiles (760 immune genes, performed with the NanoString nCounter) from peripheral blood and nasal brushing/lavage lysate samples in response to nasal spray treatment., Methods: Moderate/severe persistent dust mite AR sufferers received either AZE (125 μg/spray) nasal spray (n = 16), FP (50 μg/spray) nasal spray (n = 14) or combination spray AZE/FP (125 μg AZE and 50 μg FP/spray) (n = 14) for 7 days, twice daily. Self-reported symptom questionnaires were completed daily for the study duration. Gene expression analysis (760 immune genes) was performed with the NanoString nCounter on purified RNA from peripheral blood and nasal brushing/lavage lysate samples., Results: In nasal samples, 206 genes were significantly differentially expressed following FP treatment; 182 genes downregulated (-2.57 to -0.45 Log2 fold change [FC]), 24 genes upregulated (0.49-1.40 Log2 FC). In response to AZE/FP, only 16 genes were significantly differentially expressed; 10 genes downregulated (-1.53 to -0.58 Log2 FC), six genes upregulated (1.07-1.62 Log2 FC). Following AZE treatment only five genes were significantly differentially expressed; one gene downregulated (-1.68 Log2 FC), four genes upregulated (0.59-1.19 Log2 FC). Immune gene changes in peripheral blood samples following treatment were minimal. AR symptoms improved under all treatments, but improvements were less pronounced following AZE treatment., Conclusion: AZE/FP, FP, and AZE had diverse effects on immune gene expression profiles in nasal mucosa samples. The moderate number of genes modulated by AZE/FP indicates alternative pathways in reducing AR symptoms whilst avoiding extensive local immune suppression., (© 2021 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.)

Objective: Despite the move to at-home, small-volume collection kits to facilitate large population-based studies of faecal microbial compositional profiling, there remains limited reporting on potential impacts of faecal subsampling approaches on compositional profiles. This study aimed to compare the microbial composition from faecal subsamples (< 5 g) collected from the beginning and end of a single bowel movement in ten otherwise healthy adults (6 female, 4 male; age: 24-55 years). Microbial composition was determined by V3-V4 16s rRNA sequencing and compared between subsamples., Results: There were no significant differences in OTU count (p = 0.32) or Shannon diversity index (p = 0.29) between the subsamples. Comparison of relative abundance for identified taxa revealed very few differences between subsamples. At the lower levels of taxonomic classification differences in abundance of the Bacillales (p = 0.02) and the Eubacteriaceae family (p = 0.03), and the Eubacterium genera (p = 0.03) were noted. The observation of consistent microbial compositional profiles between faecal subsamples from the beginning and end of a single bowel movement is an important outcome for study designs employing this approach to faecal sample collection. These findings provide assurance that use of a faecal subsample for microbial composition profiling is generally representative of the gut luminal contents more broadly., (© 2022. The Author(s).)

Background: Allergic rhinitis (AR) is a complex disease involving both mucosal and systemic immune compartments. Greater understanding of the immune networks underpinning AR pathophysiology may assist with further refining disease-specific biomarkers., Objective: To compare immune gene expression profiles in nasal mucosa and peripheral blood samples between adults with AR and controls without AR., Methods: This cross-sectional study included 45 adults with moderate-severe and persistent AR (37.6 ± 12.8 years; mean ± SD) and 24 adults without AR (36.6 ± 10.2). Gene expression analysis was performed using the NanoString nCounter PanCancer Immune profiling panel (n = 730 immune genes) in combination with the panel plus probe set (n = 30 allergy-related genes) with purified RNA from peripheral blood and cell lysates prepared from combined nasal lavage and nasal brushing., Results: One hundred and thirteen genes were significantly differentially expressed in peripheral blood samples between groups (p < .05). In contrast, 14 genes were differentially expressed in nasal lysate samples between groups (p < .05). Upregulation of allergy-related genes in nasal mucosa samples in the AR group was observed. Namely, chemokines CCL17 and CCL26 are involved in the chemotaxis of key effector cells and TPSAB1 encodes tryptase, an inflammatory mediator released from activated mast cells and basophils. Six differentially expressed genes (DEGs) were in common between the nasal mucosa and blood samples. In addition, counts of specific DEGs in nasal mucosa samples were positively correlated with eosinophil and dust mite-specific immunoglobulin E (IgE) counts in blood., Conclusions and Clinical Relevance: Distinct gene expression profiles in blood and nasal mucosa samples were observed between AR sufferers and controls. The results of this study also provide evidence for a close interaction between the local site and systemic immunity. The genes identified in this study contribute to the current knowledge of AR pathophysiology and may serve as biomarkers to evaluate the effectiveness of treatment regimens, or as targets for drug discovery., (© 2021 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.)